1. Field of the Invention
The present invention relates to a cleaning device and a cleaning method for cleaning or washing an applicator nozzle for applying liquid paint with a constant thickness upon a surface of plate-like materials to be processed, such as a semiconductor wafer or a glass substrate.
2. Description of Related Art
Conventionally, in order to apply resist liquids, etc., upon a surface of a plate-like material to be processed, such as a semiconductor wafer or a glass substrate, liquid paint is applied to a center of the material to be processed, which is mounted on a spinner, so as to be spread outwardly due to centrifugal force caused due to rotation thereof on a spinner. However, with this method, almost all of the liquid paint is scattered away and the quantity remaining upon the surface of the material is very little, and therefore this is a wasteful method.
As a result, in place of the method of applying liquid by use of a spinner described above, another method has been proposed, wherein an opening having a predetermined breadth is formed in the nozzle itself so as to discharge the liquid paint, and the liquid paint is applied with the predetermined breadth opening upon the surface of the material to be processed by moving the nozzle relative to the material.
By use of such a nozzle having a discharge opening for the liquid paint with the predetermined breadth as mentioned above, although wasting the liquid paint can be avoided and effective application thereof can be done, since the nozzle has a wide breadth, a large amount of the liquid paint accumulates in the periphery of the tip of the nozzle, thereby causing generation of a contaminating substance when it dries up. Therefore, the liquid paint attached to the tip of the nozzle and at the periphery thereof must be removed therefrom by washing or cleaning after the application procedure.
As a method of cleaning, the extraneous contaminating substance adhering to the tip of the nozzle can be removed by means of a roller on which cleaning liquid is present. However, it is impossible to supply a sufficient amount of the cleaning liquid on the surface of the roller, and therefore, the liquid paint adhering to the nozzle tip cannot be removed in a short time period. Further, since the cleaning liquid dissolving the extraneous substance therein is returned back to a reservoir for cleaning liquid, the cleaning liquid is easily polluted therewith.